Synthesis of (+)- and (-)-Mellein Utilkizing an Annelation Reaction of Isoxazoles with Dimethyl 3-Oxoglutarate
摘要:
Naturally occurring dihydroisocoumarins, (+)- and (-)-mellein (2 and 3), metabolites of fungals, Cercospora sp. and Aspergillus sp., etc., were synthesized from the isoxazoles (32) and (33) by the annelation reactions with dimethyl 3-oxoglutarate.
Propylene Glycol Cyclic Sulfate as a Substitute for Propylene Oxide in Reactions with Acetylides
作者:Roderick W. Bates、Tushar B. Maiti
DOI:10.1081/scc-120015819
日期:2003.1.4
Abstract Lithium acetylides react cleanly with propylene glycol cyclicsulfate to give, after acidic hydrolysis, homopropargylic alcohols in good yield. The benzyl and TBDPS protecting groups are stable to these conditions, but the THP, TBS, acetal and orthoester groups are not. The readily available (S)-cyclic sulfate gives the (S)-alcohol without loss of stereochemical integrity.
Naturally occurring dihydroisocoumarins, (+)- and (-)-mellein (2 and 3), metabolites of fungals, Cercospora sp. and Aspergillus sp., etc., were synthesized from the isoxazoles (32) and (33) by the annelation reactions with dimethyl 3-oxoglutarate.